British Antarctic Research Group
The surprising survival techniques of Arctic sea creatures may help explain how the oldest animals on earth may have evolved earlier than the oldest fossils suggest. These primitive, primitive, and now extinct animals may have survived some of the harshest, coldest, and iciest times on Earth. The results of the research were recently published in the scientific journal “Global Change Biology”.
The fossil record we have dates the first animal existence on earth to about 572-602 million years ago, at a time when the world emerged from a great ice age, but molecular studies indicate an earlier beginning, 850 million of years ago. If true, this finding means that the animals must have survived more than one global ice age period, larger than seen since, and when much of the world was covered in ice (the “snowball” world and “snowball”). If life arose before or during these extreme glacial periods, it must have undergone conditions comparable to those of existing marine ecosystems in Antarctica and the Arctic and needed a similar survival strategy.
The expansion and contraction of ice sheets during cold and warm periods have supported the development of thousands of different plant and animal species in Antarctica over millions of years. The same element may apply to the evolution of animal life on earth. While the polar regions may seem like the most hostile environments for life to us, they are perfect places when it comes to examining the possibility and history of life in the universe beyond our planet, such as with icy moons like Europa.
British Antarctic Survey marine biologist and lead author of the study, Dr. Huw Griffiths explains: ‘This research highlights how it can teach us a lot about the evolution and survival of possible life in the past and also on other planets, as well as how some animals in the polar regions are able to adapt to life in and around glaciers at a incredible level.”
THE POLES ARE THE MOST DIFFICULT AREAS FOR LIFE
Griffiths continues: “Whether they are animals that live upside down on the bottom of the ice rather than the seabed, sponges that live under floating ice sheets hundreds of kilometers thick, creatures adapted to living in marine waters colder than -2°C , or the sun in food Sources in the dark Life in Antarctica and the Arctic thrives in conditions that would kill humans and many other animals. These cold, icy conditions help speed up the water cycle in the oceans, carry oxygen to the deep parts of the ocean, and make these areas more suitable for life.”
Floating glaciers cover more than 19 million square kilometers in the seas around Antarctica and more than 15 million square kilometers in the Arctic Ocean during the winter. Under perhaps the most extreme “snowball Earth” conditions that lasted 50 to 60 million years during the Cryogen Period, which was 720 to 635 million years ago, it is believed that the entire Earth, covering 510 million square kilometers, was covered in ice about a kilometer thick. However, there is some evidence that under these conditions the ice is thin enough for algae to survive at the equator.
Paleontologist and environmental scientist at the University of Cambridge, research co-author Dr. ‘This huge difference between the current fossil record and molecular clocks regarding the timing of the emergence of animal life means there is great uncertainty about how and where animals evolved,” says Emily Mitchell. cope with extreme environmental pressures; On the other hand, these pressures may have forced life into a more complex structure to survive.
Mitchell said: “Just as at the last glacial summit in Antarctica between 33 and 14 thousand years ago, the ice advancing in great masses would have flattened the plains and made them unfit for life, destroying the fossil remains and forcing living things to retreat into the deep sea. This reduces the probability of finding fossils from that period, while making sheltered areas and deep seas the most protected for life to develop,” he adds.
BAS polar paleontologist and study co-author Dr. Rowan Whittle says: “Paleontologists often look to the past to tell us what future climate change might look like, but this research is on the planet to help us understand the conditions under which the first animals on Earth may have been exposed, and how moderns Arctic life evolved under these extreme conditions and we sought out the coldest, most extreme habitats out there.”
Original article SciTech Daily taken from the website. (Translated by Tarkan Tufan)
